Vehicle question

[Rosscoe]

I went to Autozone today and they did a scan and it came back with the following:

"Cylinder 1 misfire condition

Probable cause:

Ignition system faulty
Fuel system faulty-Injectors or pressure
Vacuum Leak
Engine mechanical condition"

The last one really narrows things down, doesn't it? 

I chatted with a couple of guys there and we went through some scenarios. I had heard from a knowledgeable source that possibly a bad coil and that there are 3 coils for 6 cylinders so if a coil was bad, two cylinders would be dropping out AND its erratic and from what I understand, a coil works or it doesn't. No in between. Sometimes if feels like it gets worse, like another cylinder dropping out but no other misfire showed up on the computer. They asked if it just started and I said it sat all winter without me driving it and that started us thinking about the injectors. So a cheap thing to try was some injector cleaner and in the mean time I am gathering parts to do the wires, plugs, Plenum gaskets and valve cover gaskets too.
I had been meaning for a long time to check with some Mitsu dealers to see if I could find out where it had been serviced and get they history. I found the dealer in Richfield and they gave me a run down as to the maintenance they preformed. The timing belt was done at about 69,500 so its due again. He also said that on these vehicles, sometimes the valve covers start to leak and saturate the rubber tipped plug boot and make them swell and cause a misfire. He told me the plugs in there have about 70K on them. No wires were replaced. SO I am going to let the injector cleaner do its thing for a few days and continue to gather parts. I'll be putting in new NGK Iridium plugs, new wires, new timing belt and probably some related, difficult to get to parts. Boating time is coming and I bought this for a tow vehicle so I need to get it in shape. Good thing is, I don't have to drive it so I can take it apart and do it over time...if I have the correct tools. Not sure if I have to pull gears or pulleys. The dealer suggested that an entire tune up would be in order. I asked what that would run and he said about 800.00! After I got up off the floor, I asked about a timing belt change and he said around 600.00. That wasn't AS big of a shock but certainly solidified the fact, I'll have to do it myself.

[dorelse]

At least it gives you a starting point Ross!  Hope the job front also turns around for you as well.

Have you thought about getting on a Mitsu forum and seeing what others have run into?

[CVX Fever]

That's a good idea. When I had a shop tell me I had a bad hub assembly on my GMC and then saw the price to fix it I went home & googled it. There was all kinds of information pertaining to that particular problem with GM trucks on truck forums.

145K and a front wheel bearing went out yet it is still running on the original front brakes. I've got about 50% wear left i have been told,....LOL

[thedeuceman]

Quote:
from what I understand, a coil works or it doesn't. No in between.

i would have told you the same a few months ago, but had an intermittent coil on Lauries focus with a Ztec motor.
i googled and found its a common prob with that car, not sure if it relates to your prob.

[carlsoncvx18]

My company van has been in for several misfires .  They replaced the coil packs to the cyl with misfires.

[Rosscoe]

At least it gives you a starting point Ross!  Hope the job front also turns around for you as well.

Have you thought about getting on a Mitsu forum and seeing what others have run into?

I have poked around mostly looking at what the job entails, not so much about the specific issue. I'll take a look.

[V153]

I'd always been taught that a coil either works or doesn't too. But I learned a few yrs back with the 90 this is not always the case. I did in fact have a coil that would misfire when it got hot.

[Rosscoe]

I paid close attention today driving it and it doesn't start missing until its at operating temp so I do think its temp related. Doing plugs and wires may do nothing. I'm still going to do it at some point but its not as important as I once thought. I just don't think that would be intermittent. I've read some sensors can make it act like this too. I am pretty sure I can eliminate an "injector or fuel pressure, vacuum leak or engine mechanical condition" listed as possible faults with this code.
Timing belt needs to get done regardless, but I'd sure like to get this resolved first.

[Jason]

Good you found a code! Now you have to narrow it down. A misfire code can be caused by a lot of things. The nice thing is it is in one cylinder. The oil leaking into the spark plug hole could be it. Can you swap the coils around? See if the misfire follows the coil. You can do the same for the plug, plug wire, and injector. Also, when you do your spark plugs do a compression check as low compression will set off a misfire code. Could be a sticky valve, worn rings, ect. Head gasket failure will also set off a misfire code. Most of the time head gaskets go you get combustion into your coolant. (High pressure to low pressure) so you may not even see it out your tail pipe or in your oil. Napa sells a head gasket tester that looks for co2 in your coolant. It's a bubbler thing you put on your coolant reservoir and changes green if the headgaskets are bad. You can find YouTube videos on it and it works pretty well. I would almost do that before you do anything else.

[75starflight]

I agree with Jason. From what you are saying and in my experience I would swap  the coil from the problem cylinder to a different location if that is possible. You said it starts acting up once operating temp is reached? My thoughts are the coil could possibly be over heating, causing this misfire. I have also had plug wires arc with a warm engine, but not cause a problem with a cold engine. Those are the two things I would look at first.

[Rosscoe]

I have been considering swapping coils around but then I'd need to go back and have the code read again to see if it moved to another cylinder. Thats an hour drive. I'm going to check with an auto parts store that is closer then Autozone and see if they have a reader. This is the kind of thing that makes it a pain living out in the sticks.

Jason, I'd have to tear the plenum off to move plugs and wires and if I'm going to do that, they'll get replaced. Do you think a bad head gasket or warped head would cause an intermittent misfire? Wouldn't it be constant?
I am really leaning towards a coil now. Occasionally, it feels like another cylinder drops out. Unfortunately , that did not show up on the codes. If it did, I'd know if those two cylinders were on the same coil at least.
Still waiting on the Manual on dvd I ordered to see if it gives me a complete breakdown.
Thankfully this is not my daily driver and I rarely need to drive anywhere on a daily basis these days. With this and work on my trailers getting ready for spring, I have plenty to do. I have my new plugs, wires valve cover and plenum gaskets now and I think I'll order the stuff I need for the timing belt project. Once I have everything, then I'll get started.

[Jason]

Maybe just buy a cheap code reader. All you need is the number. A misfire code is alwAys 030(the cylinder number). I just had a neon with a misfire on cylinder 4. It ended up having low compression causing the code.
A head gasket could fail in just one spot. I would check it. Hopefully it's not it but at least you wouldn't waste a bunch of other money on other parts.

[Jerry]

Yer driving me nuts! Wait a week and I'll come out with my reader and test equipment (and tools)

[fireman24mn]

Ross u are welcome to borrow my code reader let me know

[Retro Performance]

If you put a timing light on the misfiring cylinder while the problem is occuring maybe you could see if the spark is interrmitent (coil problem)?

[Rosscoe]

Maybe just buy a cheap code reader. All you need is the number. A misfire code is alwAys 030(the cylinder number). I just had a neon with a misfire on cylinder 4. It ended up having low compression causing the code.
A head gasket could fail in just one spot. I would check it. Hopefully it's not it but at least you wouldn't waste a bunch of other money on other parts.

I don't even want to think about it being a head gasket.
I just ordered all the stuff needed for the timing belt. Think I'll stay focused on the miss before tackling that. I was really hoping the fuel injector cleaner might do something, being the Montero sat from last fall until this spring not being driven.

Maybe I will buy a cheap reader. Check engine light just came on in Joni's car. The stuff is piling up!

Thanks for the offer Shawn. We'll see what I can find for a cheapy.

Jerry, I wont be tearing into this for at least a week so...
I've got an inside project going on that I need to finish before a flooring installer can come.

Good idea Don. I could tell if its mate on the coil is doing it too.

Damn complicated vehicles!

[Rosscoe]

A great BIG thanks to Jason for spending his Sat helping me finish tearing down the Montero, changing valve cover gaskets, plugs, wires, water pump and timing belt. I'd still be working on it if it wasn't for his help and patience. We had some problems getting the crank pulley off however but a torch and rubber mallet helped.
We don't know if the "miss" has been addressed yet as we just got it to the point of starting it. I should know in the next couple of days. Still need to top off some fluids and take it for a drive. Hopefully this is behind me and I can get back to my boats!
Thanks again Jason. This group is awesome!